launchpad

Node.js program to control a Novation Launchpad MIDI controller. Attach handlers to react when buttons are pressed and set their colors according to your program's logic.

See ./example.js for a basic usage example.

Install

launchpad has been developed on node@8.1.4 and npm@5.3.0, though should work with any node installation that supports arrow functions, const, let, object property shorthand, destructuring.

npm i @lokua/launchpad --save
# or
yarn add @lokua/launchpad --save

API

`Launchpad(portName, options)`

Class constructor.

Params:

portName: An exact string or regexp. Defaults to /^Launchpad/
options:
- ignore0Velocity = true: Causes all registered handlers to ignore when a button is released. This is useful if you are using your Launchpad as a sequencer rather than a push & hold style instrument. For more fine grained control you can set this false and check the value parameter in any of the on* methods.
- normalize = true The Launchpad by default has some pretty odd numbering. For example, the first grid row runs from [0, 7] (as expected), but the second row runs from [16, 23]. This is not at all intuitive when it comes to mapping buttons to parameters in software etc, where one would expect the 64th button to be 63. Likewise, the top meta row sends CCs from [104, 111]. With normalize = true, the top meta row/column sends a normalized [0, 7] range, and the grid runs from [0, 63].

`Launchpad.colors: object`

off
redLow
red
amberLow
amber
yellow
greenLow
green

`#onPage(fn)`

Fired when a button in the top "special" row (buttons labeled 1-8) is pressed. fn is called with (note, value).

`#onScene(fn)`

Fired when a button in the right-most column (labelled A-H) is pressed. fn is called with (note, value).

`#onGrid(fn)`

Fired when a button in the grid is pressed. fn is called with (note, value).

Close the internal ports used to communicate with Launchpad. This only needs to be called if you wish to kill connections while your program is still running, otherwise the library will handle that automatically on process termination.